Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Iron and copper complexation by angiotensin-converting enzyme inhibitors. A study by ultraviolet spectroscopy and electrospray mass spectrometry

Captopril, enalaprilat and lisinopril, angiotensin-converting enzyme (ACE) inhibitors, are effective HO. radical scavengers and seem to have some degree of metal binding capabilities. By metal chelation iron and copper may become inactive in radical generation or the antioxidant effect can be operative by site-specific scavenging. In order to clarify the ability of the ACE inhibitors to bind iron and copper, their interactions were investigated by spectrophotometry and electrospray ionisation mass spectrometry. The spectrophotometric results showed that when iron or copper was added to the ACE inhibitors a decrease of the absorbance at 211 nm was observed. Significant modifications of the spectra in the range 250-400 nm were also observed when copper was added. An association of the ACE inhibitors with iron or copper may be inferred from these studies. The electrospray mass spectra of captopril, enalaprilat and lisinopril, when copper was added, exhibited peaks attributed to the chelation of copper by the three ACE inhibitors, with a preference for 1:1 metal : ligand stoichiometry. The electrospray data also suggest that iron is not as effective as copper for the formation of metal : ligand complexes for captopril, enalaprilat and lisinopril

Phenolic profile and biological activities of decoctions from Santolina impressa, a Portuguese endemic species

Santolina impressa Hoffmanns & Link is an aromatic Asteraceae species endemic to the southwest of Portugal. It is used in folk medicine as an herbal tea for gastrointestinal ailments and mouthwash antiseptic. The present study aimed to relate the chemical composition of decoctions from the aerial parts S. impressa with their antiacetylcholinesterase, antioxidant, antimicrobial and cytotoxic activities, in an attempt to explain the traditional use of this species. LC–MS/MS analysis identified chlorogenic acid and cynarin as the main components. Antimicrobial activity of the extracts was investigated against two cariogenic bacteria:- Streptococcus sobrinus and Streptococcus mutans, and these decoctions were not cytotoxic towards Caco-2 and HepG2 cell lines. Decoctions from capitula and stems/leaves showed high AChE inhibition, with IC50 values of 328 μg/mL and 579 μg/mL, respectively. The antioxidant activity measured using the DPPH radical scavenging assay showed an EC50 of 14.7 μg/mL and 12.9 μg/mL for capitula and stems/leaves extracts, respectively. The biological activities were kept constant after in vitro digestive process and the HPLC analysis did not indicate changes in the extract’s chemical composition. The results may explain the traditional use of S. impressa decoctions for digestive problems and as a mouthwash antiseptic.info:eu-repo/semantics/publishedVersio

Antiacetylcholinesterase activity and docking studies with chlorogenic acid, cynarin and arzanol from Helichrysum stoechas (Asteraceae)

This work was aimed at the study of the chemical composition in phenolic compounds responsible for the high antiacetylcholinesterase activity of aqueous extracts (decoctions) from Helichrysum stoechas aerial parts. Chlorogenic acid, cynarin, and arzanol were the main components of decoctions, detected by high-performance liquid chromatography with diode-array detection and liquid chromatography-mass spectrometry/mass spectrometry. Flowers and stems/leaves extracts inhibited antiacetylcholinesterase with IC50 values of 260.7 and 654.8 μg/mL, respectively. The biological activity of these extracts was maintained after in vitro gastrointestinal digestion, indicating that the active compounds present in the extracts were not enzymatically modified by the gastrointestinal system used to simulate the digestion. Molecular docking studies with the main components were carried out in order to obtain information, at the molecular level, as to how these compounds access the enzyme’s active site. The docking study showed for the first time that chlorogenic acid, cynarin, and arzanol fit nicely in the antiacetylcholinesterase active site channel, blocking all access to the catalytic triad. This explained the high inhibitory activity determined during in vitro experiments.info:eu-repo/semantics/publishedVersio